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Home My WebLink AboutMARINER POINT AT SOUTHPORT PH3 General Information GEOLOGIC SOIL INVESTIGATION of N½, Government Lot 4 Section 27, T12N, R3W, S.M. Refered to as MARILYN MYERS SUBDIVISION Prepared By: DOWLING AND ASSOCIATES 804 E. 15th Ave., Ste. 2 Anchorage, Alaska 99501 TABLE OF CONTENTS INTRODUCTION SITE DESCRIPTION SUB-SURFACE SOILS AND CONDITIONS CONCLUSION SOILS LOCATION MAP LOGS OF TEST BONINGS ADDITIONAL INFO~ATION INTRODUCTION This report is the result of a field trip investigation conducted June 20 and June 21, 1979 on the proposed Marilyn Myers Subdivision. This area is located within Section 27, ~2N, R3W, S.M. and is up De.~rmo~n Road appro~mately 2 miles. Marilyn Myers Subdivision is a newly proposed subdivision surrounded by basically unsubdivided lands and there is a small stream South of the property which is called Rabbit Creek. The proposed area is planned exclusive of public water and sewer utilities. Development of adequate sanitary facilities will be the responsibility of the individual prop- erty owner~. The sewage disposal will consist of conventional septic tanks draining into a seepage pit and/or drain field. Drawings from Department of Health and Environmental Protection. Municipality of Anchorage have been included as a part of this report of the septic system required. The water source will be from individually drilled wells. The purpose of this report is to define the soils conditions within the property and to determine the area requirements for proper sewer seepage in that particular soil. SITE DESCRIPTION Marilyn Myers Subdivision is located up DeArmoun Road approximately 2 miles East of New Seward Highway. It consists of one lot being subdivided into two (2). It has good building sites on the North 150 Feet of the lot and then slopes Southerly to the flood plain of Rabbit Creek. The creek is actually about 600 feet South of the property. The land is in its natural state. It is covered with Birch and Spruce with plush under- growth of Willows and Alders. The area is ideally suited for residential buildings. SUB-SURFACE SOILS AND OONDITIONS The surface soils found in this area are good to excellently graded sands and gravels in places. Two holes were dug with an auger to 8 feet so that a visual inspection could be made of the soils. The soils in hole ~ 1 were quite suspicious in that the entire hole from 2' to 8' was gravelly silt. (Har~. pan) G.M. to M.L. material which did not seem to be indicated In all the open cuts in the gen- eral area. The soils in hole ~ 2 were more to those of the open CUts as a sand (G.P.) with no gravel from 2' to~. No frost or perma-frost was encountered. The area is devoi~tf any recognized water table. CONCLUSIONS The two test holes on Lot 4B show a definite inconsistency in the general soils of this area. The soils of TP1 would reflect a material not condusive to septic leaching with very low percolation, yet TP2 reflects a very compatible soils for septic disposal with very high percolation. These holes display specific conditions encountered at the specific location, however, sub-surface conditions are subject to major change. Based on the information obtained in these holes, it is felt that a specific location should be located for the septic system, if hard pan is encountered the location should be relocated until sandy mat- erial is found~ therebyassuring a trouble-free septic system. If this cryteria is followed this lot should be quite suitable for on-site sewerage disposal. Specific location will require an on-site permit from DEQ. Anchorage office. DOWLING & ASSOCIATES 804 E. 15th Ave., Ste. 2 Anchorage, Alaska 99501 21 June 1979 VICINITY MAP .,.:".. i'rt PLAT OF LOTS 4A 8~ 4B MARILYN MYERS Date 'Completed ~ LOG Of' TEST BOR'I,¥G DOWLING & ASSOCIATES Engineers -- Surveyors Anchoruge,, Alosku Sase! ~.- ., of ~"'. Project Name Location __ Method Used V/eath~r SampHng Ground Vizier Table De~lh in Ft. .(.] .-- DESCRIPTION Soil type, color, t~xture, eslimoted port/cie size, - $a~pler. drlWn~ notes, depths circuloh~n Io~I, ~ole~ cn drilling ea~, blt~ u~ed, elc. LOCODbO Ho/es £ O/c~rom: Unlss~ oHerwlse noted oll sample~ ore taken w/I.~"}O Standard Pane/robin Sump;er driven ~/1~0 lb. hummer. 30 ~ d~op. DOtqLING & ASSOCIATES ~mgineers -- Surveyors ~-~,, Hole No / - Told ~epth ~ t Ground $'l~!er Toble ~mp h'nff ~SC H I ~_ ,F I O H Losd;dn MO,ts £ D~rom.. " ~- ~ [ eslimoted pcrlicle size~ . · - ] ~ ~ ~ ~ ~ ~ ~ ~ depths cir~ulohbn lost, _ ,_ _~ . _ ~~~~ ;~ -- - ~.~ ~o~ _ _ _ ;C~ i0_ .. Unless otl~rwise noted oll somple¢ ore tahen w~Z4"/O S!ondcrd Penetrohdt~ S~rnp,'er c'dnn w/140 lb. hammer. 30~ drop. Test Hole Lo9 - Description Guide e soil descriptions shown on the logs are the best estimate of the soil's ~tacteristics at the time of field cxaminacton and aa such do not achieve the :cision ufa laboratory testing prucedure. I(the 1o~ includes soils s~mple~, ~sc ~mplcs receive an indcpcndcnt tcxtuta[ classification in Iht laboratory verify the field examina¢lon. ,e logs often include the fullowhsg items: ?.~t~.th Intc_rv_.a_[ -- usually shown to 0,1 foot, within that zone no sign~ change in soil type was observed through drill action, direct observation ur sampling. Frost Classification - NFS, Fl, F2, F3, F4, see "Soil Classification Chart*' Texture of Soil - Ancngineerlng classification of the soils by particle size ..~d proportion, see "Soi[ Ciassificatiun Chart", note thc prop. rtt.n~ .~r¢ appruxim,atc and modifications to the soil Broup due {u stratification, inclusions and changus m properties ate included. dry:, no u~ htttc app.ircnt surface moisture, damp. mot, sure forms portion ut'color, less than plastic limit, saturated, free water may be squeezed out, ifa free draining soil; ~nd. (Thc moisture content is further defined by reference to LW,NP M%ordilatency,I mixttuc~ wah ol wubout a fmc f~act~on, derived from drilling action and/or sample data; usually described;~s: very loose, loose, medium dense, very dense. General intent is to 13ortray earthwork Stiffness - refers to more-or.less cohesive soils and fine grained silts of ~stlt groups. L.¢tlved I'[om drill action and/or sample data. Very soft, soft, stiff, very still and hard arc commonly used ~crms. Particle size -- The largest particle recovered by the split spoon is 1-3/8". Shclb) tube Y', auger flights {minute-man) 2", Auger flights {P~50 hollow stem) 6"-8". Larger particles are described indirectly by action of thc drilling and arc referred to as cobbles, 3" to 8", or boulders 8"+. Therefore when rcviewmg the gradation sheets, if any, the description on the bole log must be considered for an'indication of lar~er ~rticle/. Unified Soil Cl.,ssification - This is a two letter code. See Unified ~fic~tiun ~heet I'~-r-~hcr definition. In some cases A^SHO and/or FAA soil cl~ssificat.ons may be shown as well as the unified. Atretbcrg Limits - u~:ful loc fine grained and other plastic soils. P_]l; natural moisture content believed to be less than plastic limit natural moisture content believed to be between plastic and liquid ~-mit s L.__~; natural moisture consent believed to be greater than liquid limit N~P; non-plastic, useful as a modifying description of some silty mat~ti~ls. Dilatencv - is the abdity of water to migrate to the surface of a ~turated ut ncarly saturated sot[ sample when vibrated or jolted -- used as ~n ,~id to dcteHnme il'a fine grained soil is · slightly os non-plastic silt ur a volcanic ash. Rock flour - finely ground soil that is not plastic but otherwise appears ~ clayey silt. Organic Content - usually described as Peat, PT, sometimes includes discrete particles such as wood, coal, etc. ~s a modifier to an inorgamc soil. Quantity described as; trace, or an estimate of volume, or, in ca~c of all organic, - as Peat. This may include tundra, muskeg and bog material, Muck - a modifier used to describe very soft, semi-organic deposits usually occuring below a peat deposit. Amorphus peat ~- organic particles nearly or fully disintegrated. Fibrous Peat - organic particles more-or-less intact. Bottom of Tcsthole - mcludes last sample interval. Frost Line - seasonal frost depth as described by drilling action and/or samples at the time of drilling. Frozen Ground - other than frost line, described by s;*mples, usually mcludes description o( icc content, often will include modified Umficd Classification for frozen soils - this is a special c,~se related to permafrost studies. Free Water Level - The free water level noted during drilling. This is not necessarily the static water table at the time of drilling or at otl~er seasons. Static water table determmation in other than very permeable soils requires observation wells or piezometcr installations, used only m special cases, Blow/6" - The number of blows of a 140 weight free falling 30" to advance a 2" split spoon 6"i the number of blows for a 12" advance is. by definition, the standard penetration. ,4% - natural moisture content of the soil sample, usually not pc-~-fr ormed on clean sands or gravels below the water table. ~¥pe ofSample - SP, re(ers to 2" split spoon driven into the soil by 140 pound weight, a disturbed sample, ~, thin wall tuhe, "Shelby" u~:d to obtain undisturbed samples of fine grained soil, G, "grab" disturbed sample from auger flights or w~il of trench. C, cut sample, undisturbed sample from wall of trench. Dr}' Strenl.~th - a s~seful indicator of a soil's clayey fraction, N=None, L=Low, M=Medium, H=High - The samples are placed into apparently sinular groups based or and texture and are arbitrarily assigned a group '.ester. Further disturbed tests including A.erberg Limits. grain site, moisture-density relation:~hsp, etc. may be pcrfmmed on the group and ;*re a~sumed to reflect tl~e general distrubed cls.~racteristics of the soils as4gned to the group. This ~s an impnrtant phase of the sod attalysJs and is used Lo standardize thc varmus qualitative dctcrnfinat~ons and to reduce the number of quantitative tests necessary to describe thc ,lull mass. SOIL CLASSIFICATION CHART 30% GRAVEL CLAY CLAYEY CLAYEY \ OR\ OR SILTY SAND CLAYEY SILTY SILTY CLAYEY GRAVELLY SAND SANDY GRAVEL SILTY GRAVEL GRAVEL (+#4 SCREEN) % BY WEIGHT NONFROST SUSCEPTIBLE SOILS ARE INORGANIC SOILS CONTAINING LESS THAN 3% FINER THAN 0.02 mm. GROUPS OF FROST-SUSCEPTIBLE SOILS; GRAVELLY SOILS CONTAINING BETWEEN 3 AND 20% FINER THAN 0.02 mm. F2 SANDY SOILS CONTAINING BETWEEN 3 AND ]5% FINER THAN 0.02 mm, F3 a. GRAVELLY SOILS CONTAINING MORE THAN 20% FINER TFIAN 0,02mm. AND SANDY SOILS {EXCEP'r FINE SILTY, SANDS) CONTAINING MORE THAN ]5% FINER THAN 0,02 mm, b, CLAYS WITH PLASTICITY INDEXES OF MORE THAN 12. EXCEPT VARVED CLAYS, F4 a. ALL SILTS INCLUDING SANDY SILTS. b. FINE SILTY SANDS CONTAINING MORE THAN 15% FINER THAN 0.02 mm, C. LEAN CLAYS WITH PLASTICITY INDEXES OF LESS THAN 12. d. VARVED CLAYS, / SAND GRAVELLY SAND SANDY GRAVEL EL ¥ V 0 10 20 30 40 50 60 70 80 90 100 '~',, p,!,tlllllli{I I ? Municipality of Anchorage DEPARTMENT OFHEAL/~-~'& ENVIRONMENTALPROTECTIO~ ~.64-4720 PRE-INSPECTION CHECK SHEET TYPICAL TRENCH ON LEVEL TOPOGRAPHY MINIMUM WELL DISTANCES: INDIVIDUAL TO TANK 100' TO TRENCH 100' CLASS A, B PUBLIC - Over 25 Service or More Than 15 Connects TO TANK 200' TO TRENCH 200' CLASS C PUBLIC - Under 25 Service or Less Than 15 Connects TO TANK 150' TO TRENCH 150' Public wells must have dedicated protective radius recorded on the S/D plat. Adequate engineering plans Minimum 5' cast iron are required into undisturbed soil(4" ~DiDe) Plastic Pipe ASTM D3034 may be used in place of the cast iron. 4" CAST IRON CLEANOUT WITH AIRTIGHT CAP C1 CLEANOUT WITH AIRTIGHT CAP ALL CLEANOUTS MUST COME AT LEAST TO GROUND LEVEL ~ PERFORATED PiPE INSTALLED LEVEL [] replacement site ~ MINIMUM J 2x gravel depth Perforated Pipe ;........". ~ -,..,' , .. (Perforations Do~ olid Pipe with cap Perforated Pipe SEEPAGE TRENCH INSTALLED ACCORDING TO SOIL TEST [] SEPTIC TANK MUNtCIPALII,'~' APPROVED [J INLET AND OUTLET OF SEPTIC TANK WATERTIGHT [] TRENCH INSTALLED ACROSS SLOPE PERFORATED PIPE LEVEL LINE BETWEEN TANK ~ND HOUSE 2% to 6% SLOPE NOTE: I00' MINIMUM FROM TANK AND TRENCH TO RIVER, LAKE OR STREAM [] Excavation to Bottom of seepage trench 4' lot line 10' Minimum above water table And 6' minimum above bedrock ( ) RAKE SIDEWALLS BEFORE INSTALLING GRAVEL [] ~..___.~, ,~. .r~.. Municipality of Anchorage ¢~'. DEPARTMENT OF HEALTH & ENVIRONMENTAL PROI'E~, (ION PRE.INSPECTION CHECK SHEET 264-4720 MINIMUM [] SEPTIC LEVEL 4" CAST IRON SIPHON PIPE WITH AIBTIGItT CAPS I1 ~'"'""~ 1 UNDISTURBED SOIL MINIMUM TO EDGE OF EXCAVATION E] CAST IRON REQUIRED WHENEVER LINE CROSSES UNDER DRIVEWAY E3 crib or Log GRAVEL BACKFILL CRIB 4' MINIMUM ABOVE WATER TABLE [] 6' MINIMUM ABOVE BEOROCK [] MINIMUM WELL DISTANCES: INDIVIDUAL TO TANK 100' [] TO PIT 100' ,m NO SEWER LINE 10'Lq PUBLIC - Under 25 Service or Less Than 15 Connects TO TANK 100' ( ) TO PIT 150 ' 75'-100' ONLY CAST IRON SEWER LINE PUBLIC- Over 25 Service or More Than 15 Connects TO TANK 200' ( ) TO PIT 200' ( ) 100'-200' ONLY CAST IRON SEWER LINE 100' NO SOURCE OF CONT~XlINATION NOTE: 100'MINIbIUM FROM TANK AND PIT RIVER, LAKE OR STREAM ( ) Individual 4" SEWER LINE [] . CONSIDER DISTANCE TOABEAWELLS&SEWERSYSTEMS[] PiT EXCAVATION BASED ON SOIL TEST [] SEPTIC TANK MUNICIPALITY APPROVED [] ItOUSE INLET & OUTLET MUST 5' BE WATERTIGHT '~ SEPTIC TANK GRADE: 2' PER I00' '/," PER FOOT EXCEPT PRECEEDING TANK ANI SHOULD NOT EXCEED 6" PER 100' ON Fb TERRAINS [] SEEPAGE PII' SEEPAGE PIT CRt8 SCREENED GRAVEL ½" - 2%" 20' MINIMUMTO NEAREST LOT LINE Date ~ring No, S~ple No.~ Tot~ ~ in ~r~s of s~ple~ Ws : Wt in gr~s of material ) No. k sieve : IJ, S,. Sie~ Openings Standard Weight Percent Retained Percent .... Sieve Size Retained I~, Finer Znches Millimeters or N~ber in gr~s P~rtial Total by Weight 3.00 3-in. ~ .~ R-in. 1.O0 25.4 1-i~. o.7~o ~9.z 3/k-~. o.25o 6.35 ~o. 3 0.13~ 3.~ No. 6 o.o~k a. 38 ~o. 8 0,0~ 1.19 ~o. 16 0.033 0.8~ ~o. 20 o.o2~ .. o.59 ~o. 3o 0.0165 0.~2 No. O.Oll7 0.2~7 No. 50 0.0083 0.210 Mo. 70 0.0059 0.149 No. l~ ~' '1, '~ '/ ~ ' ~ O.00kl 0,105 No. 140 0.0029 O.OTk No. 200 'f ' Total ~eight in gr~s,